Help with insulating the base

[hmc3142]

hi everyone, can someone tell me how I insulate the base of what a round wfo will be sitting on? What order and how many inches. For instance, from the bottom up, you put cement, then what is next layer, then next , then next until you lay your firebrick oven floor. Thanks so, so much!

[fxpose]

Here ya go:

http://www.fornobravo.com/forum/f8/p...load-1674.html (Pompeii Plans Ready for Download)

[dmun]

In brief, the oven rests on a reinforced concrete slab, four inches or so. On top of this is your insulation, either four inches of vermiculite concrete, or two inches of refractory insulation board. If using vermiculite, a leveling mixture of sand and fireclay is put down, then the firebrick floor. Most everyone lays the firebrick flat, for two and a quarter inches.

[hmc3142]

Hi Dmun...Thanks for the great advice. I want to insulate well and not skimp on any conditions. Can you please tell me how you would insulate the firebrick dome in the order that it goes and how many inches of the insulation. Thanks so much!

[Eric Pfeifer]

I insulated my base with one inch of percrete on top of the structural slab, plus two inches of FB board. A full hot burn at equilibrium on my oven does not get the opposite side of the structural slab more than about 100 or so degrees--basically a hot Minnesota summer.

[hmc3142]

Hi Eric,

Is percrete perlite and concrete? FB board is what kind of board? Thanks so much!

[dmun]

Is percrete perlite and concrete?

Perlite (or vermiculite) and portland cement. The perlite is a lightweight aggregate, not a concrete additive.

FB board is what kind of board?

Refractory mineral fiber board. I used insblock19. There are lots of brands, and a more expensive alternative, calcium-silicate (cal-sil) board.

[Eric Pfeifer]

Dmun beat me to it! Best wishes on your build!

[hmc3142]

Thanks everyone for all of your great help! Mina